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Tuning a position axis, Tuning a position axis -7, 2 tuning a position axis – Delta RMC101 User Manual

Page 35

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Setup Details 2.2

Starting Up the RMC

2-7

can tune the axis. Remember to set these bits to either "Soft Stop" or "Hard Stop" when you
have gained sufficient control of the axis. This may not be possible on some systems because
of safety concerns.

• When changing the parameters, remember that they are not updated in the RMC until the Set

Parameters (P) command is issued. They are not stored into the RMC Flash memory until the
Update Flash command is issued.

2.2.3.2 Tuning a Position Axis


The following procedure may be used to tune many position axes, hydraulic axes and motors in
velocity mode. Please read the Tuning Overview before following this procedure.

There is no substitute for experience when tuning an axis. This procedure offers some guidelines,
tips, and suggestions for tuning your system. While these steps will work for some systems, they
may not be the best for a particular system.

Tuning Procedure

1. Do Open Loop Move

This step is for verifying that the system wiring and setup is correct before doing any closed loop
control. Issue an Open Loop (O) command with a small drive, such as 50-150. Increase the drive
until the axis begins to move. A positive drive should yield increasing counts. Issue an Open Loop
command again with a negative drive. This should yield negative counts.

Before continuing, verify that all the Gains and Feed Forwards are set to zero.

2. Check Dead Band

If your system has a large dead band, you will need to set the Dead Band Eliminator value. To
find your dead band, give increasing amounts of drive to the system with the Open Loop
command. The value of drive at which the system starts to move is your dead band. If this value
is approximately 400 or greater, the Dead Band Eliminator should probably be used. If it is less, it
is left to the discretion of the designer.

3. Adjust the Proportional Gain

The Proportional Gain must be adjusted to gain some control over the system for continuing the
tuning procedure. Adjust the Proportional Gain by slowly increasing it and making moves. When
the system gets close to final position reasonably quickly, continue to the next step. If the system
begins to oscillate, decrease the gain.

4. Adjust the Feed Forwards

In many hydraulic systems the feed forward parameters (Extend Feed Forward and Retract Feed
Forward) are the most important parameters for position tracking during a move. These may be
adjusted in 2 ways:

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